How to feed an emaciated dog.

Milaia came to us quite skinny and malnourished. She has gained a bit and I've only been feeding her as much as a dog of the weight she should be should be fed. My mother wants me to feed her more than this so as to get her weight up faster, but I'm not sure if a significant gain in weight in a short amount of time is healthy.

She is getting surgery on her leg next week though and my mother feels as if it'd be safer if she were a proper weight before then. I agree. But she is not extremely skinny, she acts pretty healthy, and according to things I've read the health risks of bringing her weight up fast outweigh her getting surgery underweight.

What is the best way to feed her? Should I continue feeding as I am or should I be giving her more?
I'm feeding her two cups of dog food twice a day.

depends how skinny she really is,most dogs carry extra weight,that and it may be body condition that is lacking but that will come with time,

if she is very underweight 4 smaller meals of very good quality rather than two larger is preferable,try and over feed and it will defeat the object as she will prob get dire rear.

With thin dogs you feed to the weight you want them to be.
With starved dogs, you have to feed little and often and be careful not to overload them.
You could also feed her foods that encourage weight gain like tripe and lamb (raw).